In-Plane Heterostructured MoN/MoC Nanosheets with Enhanced Interfacial Charge Transfer for Superior Pseudocapacitive Storage

作者：Wang, Cheng; Li, Xiuli; Song, Hao; Chu, Paul K.; Huo, Kaifu^*

来源：Advanced Functional Materials, 2023.

DOI：10.1002/adfm.202311040

• 2D nanosheets
• in-plane heterostructure
• molybdenum nitrides
• pseudocapacitance
• supercapacitor

2D transition metal carbide/nitride heterostructures are emerging pseudocapacitive materials for supercapacitors (SCs); however, the lack of efficient synthesis methods and an in-depth understanding of the pseudocapacitive storage mechanism of these potentially important materials impede their applications in SCs. Herein, 2D MoN/MoC nanosheets with a precisely regulated interface are prepared controllably by a scalable salt-assisted method with bulk MoS2 as the precursor. In operando infrared spectroscopy and electrochemical quartz crystal microbalance results reveal that the pseudocapacitance of the MoN/MoC nanosheets originates from the reversible reaction between Mo-N sites and H+ in the acidic electrolyte. Density-functional theory calculations and X-ray photoelectron spectroscopy disclose that the MoC/MoN heterointerface induces the internal electric field from the accumulated negative charges at the Mo-N sites by electron donation from MoC, leading to enhanced H+ adsorption at the Mo-N sites and superior pseudocapacitive storage. The heterostructured MoN/MoC nanosheets show a large volumetric capacity of 1045.3 F cm-3 at 1 A cm-3, high-rate capability of 702.8 F cm-3 at 10 A cm-3, and superior cyclability with capacity retention of 98% after 10,000 cycles, which outperform reported Mo-based carbides and nitrides. The results provide new insights into the development of high-performance 2D heterostructured materials for superior pseudocapacitive storage. @@@ The 2D heterostructural MoN/MoC nanosheets with a precisely regulated interface prepared controllably from the bulk MoS2 precursor show a large specific volumetric capacity (1045.3 F cm-3 at 1 A cm-3) and high-rate capability (702.8 F cm-3 at 10 A cm-3) due to fast charge transfer and enhanced ion absorption at the in-plane heterointerface.image

• 单位
  华中科技大学